Splintering Grooves - shaper

[Mike Berrevoets]

I'm making a bunch of shaker style doors on a shaper for our kitchen remodel. On quite a few pieces I'm getting splintering on the edge of the grooves when running the grooves. I'm wondering if it is my technique, the material, or just the nature of the beast.

Here's some specifics:

Shaper is an old Delta with my home made fence boards.
infeed and outfeed fences are on the same plane so I'm not taking material off the edges, I'm just cutting the groove.
the bit set is from Infinity and is new or nearly new. I've run maybe a hundred feet or so through it at most.
wood is hard maple, will be clear finish
I don't have a power feeder and don't plan to get one.
I'm using a finger board in front of the bit and another one behind the bit.
I use some push blocks to keep my fingers away from the bit.


I'm trying to select the edge so the bit goes with the grain but that is not always possible while keeping the "good face" down.

I've tried slower feed speed and faster feed. it doesn't seem to matter too much.

Is this just something I need to accept if I'm not willing to invest in a power feeder? Maybe sand out the minor splinters and re-make the ones that are too bad?

[Martin Wasner]

What diameter cutters? What rpm? How many horsepower shaper?

Do the cutters have a sharp edge in the groove or eased edge?

[Martin Wasner]

How many wings too

[Mike Berrevoets]

The cutters are 3 wing with 2 5/8" diameter. sharp edge in the groove.

Here is a link http://www.infinitytools.com/shaper-cutters-accessories/carbide-shaper-cutters/door-making-shaper-cutters/rail-stile-for-cabinet-door-shaper-cutters

I think the shaper is only 2 hp and I have no idea of the RPM as it only has one speed. It doesn't "bog down" at all when cutting.

Sorry, kind of flying blind. I bought the shaper used just for this kitchen remodel. I'm getting better and more consistent results then I did with the router table and a similar profile set and I don't have to listen to the router whine. if I could cut down on this splintering then I'd be happy.

[larry senen]

very common problem. the quickest fix is to climb cut maybe a 1/6" of the groove. a little scary on a shaper!!!. i run my doors on a router table with a power feeder and set the feeder to make the cut. without a feeder you might be able to set up a safe way on a shaper but,,, i'd try a separate set up on a router table. maybe run them vertical with a 1/4" bit.

[rudy de haas]

I have had the same problem and am hoping, now that you've brought it up, that someone provides an "ah ha!" answer. Meanwhile:

1) I bought my shaper used - but in the process of buying it I looked at several others too. One of those was a small delta that looked like an overly ambitious router and had a slightly loose (the top precessed) spindle - with a heavy bit that thing shook and I could see that splintering thin edges in a very dry, somewhat hard, wood like maple.

2) in cutting hickory on my shaper (3HP 90s grizzly, looks like a delta) I've discovered that it splinters easily when cut against the grain - but I can't always tell which way is right until it's too late. As a workaround I do an initial cut that's very shallow and that not only tells me which way to go, but seems to reduce splintering on its own too.

[Mel Fulks]

I think the one speed deltas are about 7500 rpm, too slow for small diameter carbide. Agree with a shallow climb cut followed by forward pass. Watch for the old steel cutters ,sometimes there's a box of them cheap at yard sales.

[J.R. Rutter]

You could try making a zero clearance fence plate with some thin plywood. The side benefit is that it will completely shield everything that doesn't poke through the front of the plate. This will make climb skim cutting a bit safer, if you still need to do it. You could also try skim cutting with normal feed before doing the full depth.

Industrial cutter sets get around this by letting you machine away the entire edge. Some difficult woods might have a small percentage of slight edge splintering, but in general it works very well.

[Max Neu]

Set the infeed fence in 1/32"- 1/16" and the problem will go away.

[Mark Wooden]

Make a very light- 1/32" or so- cut as a first pass, then set for full depth and complete the groove.

[Wayne Lomman]

Max Neu is 100% right. Do this and problem solved.

If you don't you need a different cutter set where it has cutting edges that plane the internal faces of the groove. My 150 x 50 mm straight cutter has this feature. Edges are perfect. Cheers

[Jeff Duncan]

Your best bet is to remove a small amount of the edge as well as the groove, it's not the only way to do it, but IMO the best and easiest way to go. Taking off about a 32nd or so will give you a nice clean edge for your joint.

good luck,
JeffD

[Mike Berrevoets]

thanks all. I think I'll try taking off 1/32 or so of the full edge and see how that works first.

if I'm still getting splintering I'll look at doing a zero clearance plate. I just haven't figured out how I can do that reasonably safely. I like my fingers well away from the bit on this thing.

[Kevin Jenness]

Another way to suppress tearout is to score the groove edges with a mortise gauge. Be cautious about mixing hand feeding and climb cutting. Max's way works but requires accurate setup to avoid sniping.

[J.R. Rutter]

I assumed that you were just using a groover instead of a full edge cutter...

[mreza Salav]

I find that is common with maple. The suggestion of a shallow cut and then deep cut works. Or if you have a power feeder, try climb cutting all of it.

[Wayne Lomman]

Reading back over these, I see I missed the references to climb cutting. DON'T DO IT WITHOUT A POWER FEEDER. It's just too dangerous by hand. I have had two colleagues lose the majority of their fingers exactly this way. Also a zero clearance fence out of thin material is no protection at all. I have also seen the consequences of reliance on a thin fence.

[Kevin Jenness]

I missed the link to your shaper cutters, and assumed that when you said "shaker style" you were just using a groover with a square edge. As your set will tool the entire workpiece edge,the best way is as Max suggested, mill enough off the edge to remove the tearout. The outfeed fence half must be set exactly in line with the edge coming off the cutter and parallel to the infeed fence to avoid snipe, as with a jointer. This problem can be avoided with a power feed and an outboard fence.

[J.R. Rutter]

Also a zero clearance fence out of thin material is no protection at all. I have also seen the consequences of reliance on a thin fence.

The main benefit is that the part will never get pulled into any gap that might exist in the fence. Of course, you still need to be aware that the cutter is there. If it was just a groover, like I originally thought based on his having tearout, then a zero clearance fence is an improvement in safety, imho.

[Wayne Lomman]

Apologies for making a point of this but zero clearance fences protect the workpiece, not the operator. Awareness is a start but thin fences are an illusion of safety. You still need finger protection. We are talking about immediate and catastrophic consequences that occur faster than human reaction time.

[J.R. Rutter]

Well short of having a power feed, which op doesn't have, a fence that provides continuous contact for the workpiece will be safer than a split fence. Think table saw with a zero clearance throat plate vs a generic universal plate. The cutter is still exposed, so that does not stop being a hazard, but proper continuous support as the part moves past the cutter is good for both the part and the operator.

[Wayne Lomman]

What I am speaking against is the recommendation to use a thin zero clearance fence with no other regard for safety. The analogy of the saw is not the same at all - a saw has its standard guarding. A spindle moulder/shaper has to have cutter guarding set up each time. I could go on ad nauseum about this but I won't until I decide to start a safety thread. The general attitude to safety appears haphazard but there are systems available for a routine and considered approach to safety that anyone can learn. I will be back in Adelaide tonight where I have the resources filed at the moment. If the moderators don't consider it too inflammatory, I will start a discussion about safety and how to manage it. Cheers

[Mike Berrevoets]

I appreciate the discussion. Rest assured, I'm responsible for my actions. I won't be climb cutting anything. I didn't take the "thin zero clearance" plate to be something so thin it couldn't support the workpiece.

I use feather boards. I use push blocks to keep my fingers well away from the bit. I think the biggest safety issue I have right now is the gap around the bit and the possibility a small piece could catch and fly. I'll rectify that this weekend when I have some time to get back in the shop.

Shapers scare me enough that I have a healthy respect for them and am doing things on a shaper safety wise that I'd never bother to do on a router table.